Nanoparticles Help Creation of Resistant Welding Joints

TEHRAN (INIC)- Iranian researchers from University of Tehran succeeded in increasing the mechanical and metallurgical properties of welding joints by using nanoparticles in friction stir welding method.

Results of the research can have applications in automotive, railways and aerospace industries due to the wide applications of the joints in different industries.

Although aluminum alloys are widely used, some joints of aluminum alloys have limitations after the application of usual welding method. In addition, welding joints usually have different properties from other parts of the object. Therefore, researchers try to improve the performance of the joints.

The aim of the research was to improve the mechanical and metallurgical properties of welding joints of two types of aluminum alloys with various properties by using nanoparticles. Taking into consideration the improvement in some mechanical and metallurgical properties of nanocomposite joints, these joints have longer lifetime. Therefore, the maintenance and replacement of the joints are carried out at longer intervals, which results in decreasing the costs.

In this research, stir friction welding method has been used to join two various types of aluminum alloys, one of which has significant corrosive properties and the other one has a perfect ratio of strength to mass. Alumina nanoparticles have been used in stir friction welding method to improve the properties of the joints. The application of nanoparticles creates a nanocomposite area in the welding zone, which contains an aluminum alloy phase as the bed and alumina nanoparticles as the dispersed phase.

Comparison between test results of reinforced joints with nanoparticles and regular ones shows that corrosion resistance, abrasion resistance and the toughness of the reinforced joints have improved.

Results of the research have been published in Materials Research, vol. 18, issue 6, 2015, 1156-1162.